Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 129

=PHILOS'OPHER'S STONE.= _Syn._ LAPIS PHILOSOPHORUM, L. A wonderful substance, the discovery of which formed the day dreams of the alchemists.

It was supposed to be capable of converting all the baser metals into gold, and of curing all diseases. Some of the alchemists appear to have laboured under the delusion that they had actually discovered it. The last of these enthusiasts was the talented and unfortunate Dr Price, of Guildford. Speaking of the age of alchemy, Liebig says:--"The idea of the trans.m.u.tability of metals stood in the most perfect harmony with all the observations and all the knowledge of that age, and in contradiction to none of these. In the first stage of the development of science, the alchemists could not possibly have any other notions of the nature of metals than those which they actually held.... We hear it said that the idea of the philosopher's stone was an error; but all our views have been developed from errors, and that which today we regard as truth in chemistry may, perhaps, before to-morrow, be regarded as a fallacy."

=PHILOSOPH'IC CANDLE.= An inflamed jet of hydrogen gas.

=PHILOSOPHIC WOOL.= Flowers of zinc.

=PHIL'TRE.= _Syn._ PHILTRUM, L. A charm or potion to excite love. The ancients had great faith in such remedies. Nothing certain is now known respecting their composition; but there is sufficient evidence that recourse was frequently had to them by the ancients, and that "their operation was so violent that many persons lost their lives and their reason by their means." The Thessalian philtres were those most celebrated. (Juv., vi, 610, &c.) At the present day the administration of preparations of the kind is interdicted by law.

=PHLORE'TIN.= C_{15}H_{14}O_{5}. A crystallisable, sweet substance, formed along with grape sugar, when phloridzin is acted on by dilute acids.

=PHLORID'ZIN.= C_{21}H_{24}O_{10}. _Syn._ PHLORIZINE; PHLORIDZINUM, L.

Prep. By acting on the fresh root-bark of the apple, pear, or plum tree, with boiling rectified spirit; the spirit is distilled off, and the phloridzin crystallises out of the residual liquor as it cools.

_Prop., &c._ Fine, colourless, silky needles, freely soluble in rectified spirit and in hot water, but requiring 1000 parts of cold water for its solution; its taste is bitter and astringent. When its solution is boiled with a little dilute sulphuric acid or hydrochloric acid, it is changed into grape sugar and phloretin.

Phloridzin bears a great likeness to salicin. It is said to be a powerful febrifuge.--_Dose_, 3 to 15 gr.

=PHOCE'NIC ACID.= See DELPHINIC ACID.

=PHNIC'INE.= See INDIGO PURPLE.

=PHO'NOGRAPH.= Some years back Prof. Faber, of Vienna, constructed and exhibited in the chief cities of Europe 'a talking machine,' which was able to articulate simple words and sentences with considerable distinctness. The complex mechanism by which this was effected was contrived upon the principles of the human organs of speech, as the machine possessed an india-rubber tongue and lips, and an artificial larynx, made out of a thin vibrating tube of ivory. Faber's automaton, although of much greater scientific interest than the automatic flute and flageolet players of Vancanson, the trumpeter of Droz, and similar exhibitions of curious workmanship, was, like these, only a mechanical curiosity, without any promise of a useful application.

Entirely distinct from Faber's machine, not only structurally and in the method by which it produces its effects, but also in the end designed for it by its inventor being an essentially practical one, is the 'speaking machine or phonograph' of Mr Edison.

The first impression that will occur to those who having heard Mr Edison's instrument speak have subsequently made themselves acquainted with its construction, will probably be one of surprise that an effect so apparently startling as that which it has been able to produce should be accomplished by means so simple.

[Ill.u.s.tration]

B is a bra.s.s cylinder, through whose centre pa.s.ses a metal shaft, the arms of which rest on upright supports, one of which is shown in the engraving.

The arm of the shaft, obscured from view, corresponding in length with the part of it which is visible, is screw-turned, and it works in a nut bored out of the support. Attached to the screw-end of the shaft or axle is a crank C, by turning which a double movement, viz. a rotatory and a horizontal one, may be simultaneously imparted to the cylinder. Round the surface of the cylinder is cut a spiral groove corresponding in dimensions with the threads of the screw part of the shaft. Covering the whole of the cylinder is a sheet of tin-foil, which is secured to its edges by means of sh.e.l.l-lac varnish. In front of the cylinder, resting on a proper support, is a mouth-piece, A, at the bottom of which (the end nearest the cylinder) is a very thin plate or diaphragm of metal, and to this diaphragm is attached a round steel point, which when not in use does not touch the foil. Previously to using the apparatus this steel point has to be accurately adjusted opposite to that part of the foil lying over the spiral groove. If now the lips be applied to the mouth-piece, and any sentence be spoken, the crank being at the same time turned, the vibrations imparted to the metal plate by the voice will cause the steel point to come into contact with that part of the foil overlying the groove in the cylinder, and to make on the foil a number of indentations, as it revolves, and is carried forward laterally before the mouth-piece.

Furthermore these indentations will be found to vary in depth and sectional outline according to the nature of the vibrations which have produced them; and as experiment proves, are the specific and infallible caligraphy of those vibrations.

"It might be said that at this point the machine has already become a complete phonograph or sound writer, but it yet remains to translate the remarks made. Now, there is no doubt that by practice and the aid of a magnifier it would be possible to read phonetically Mr Edison's record of dots and dashes,[95] but he saves us that trouble by literally making it read itself. The distinction is the same, as if, instead of perusing a book ourselves, we drop it into a machine, set the latter in motion, and behold! the voice of the author is heard repeating his own composition.

The reading mechanism is nothing but another diaphragm, held in the tube D, on the opposite side of the machine, and a point of metal, which is held against the tin-foil on the cylinder by a delicate spring.

[Footnote 95: According to the 'Polytechnic Review,' Mr Edison does not appear to have yet solved the problem of reading the phonograph record by sight. He states that although a specific form exists for each articulated sound, the chief difficulties arise from the varying indentations or marks caused by the same sound. Amongst the circ.u.mstances giving rise to these results are: the same sound uttered by different people, the manner in which it is spoken, the distance of the mouth from the instrument, the force with which it is spoken, or the speed with which the barrel is rotated.]

"It makes no difference as to the vibrations produced, whether a nail moves over a file or a file moves over a nail, and in the present instance it is the foil or indented foil-strip which moves, and the metal point is caused to vibrate as it is affected by the pa.s.sage of the indentations.

The vibrations, however, of this point must be precisely the same as those of the other points which made the indentations, and these vibrations transmitted to a second membrane, must cause the latter to vibrate similar to the first membrane, and the result is a synthesis of the sounds, which in the beginning we saw, as it were, a.n.a.lysed."[96]

[Footnote 96: 'Scientific American,' December, 1877.]

In some of the later instruments, that section of the apparatus shown at D is dispensed with, and the reproduction of the spoken words or sentences is effected by bringing the cylinder back to its original starting point, opposite to the little steel projection attached to the metal disc at the end of the mouth-piece A. The steel point is then brought by means of a screw into contact with the foil, and as the cylinder moves onward in its former track, the metal point retraces the indentations on the foil from beginning to end, in doing which it communicates the vibrations it thus receives to the metal diaphragm in precisely the same manner, and with the same results as were shown with D. For the diaphragm, more particularly when employed as a resonator or reproducer of the words which have been spoken into the mouth-piece, other substances than metal have been tried, with, it is said, more satisfactory results. One of these is paper, the sounds given off by which are stated to be more distinct than those from iron.

Dr Clarence Holt, of Boston, in a communication to Mr W. H. Preece, writes that he has "constructed a diaphragm upon the principle of the membrane of the human drum of the ear, to be used as a reproducing disc." Dr Holt continues "that his object was to employ a membrane which from its structure and shape would reproduce the lighter over-tones representing the quality of the voice, and at the same time cut off the sharper exaggerated over-tones embossed as such by the metal disc upon the tinfoil. He says the results of his experiments with such a membrane were very gratifying, and that the material of which it may be made should be either stout felted paper (to be varnished on the outer surface when used for speaking) or drum head moistened and pressed into a concave form before using."[97]

[Footnote 97: Published in 'Nature,' February 4th, 1878.]

The crank (shown in the figure) by which the cylinder is turned is very frequently supplanted by an apparatus consisting of weights and wheels, or else by clockwork, whereby the cylinder is put in motion. The advantage of the working of these arrangements over that of the crank are, that instead of an inequality a regularity of movement of the cylinder is ensured, and it is thus made to advance at the same rate whilst the words are being reproduced as when they are being spoken.

One of the effects of this uniformity of the rotation of the cylinder under its two modes of action is to reproduce the exact pitch or tone of the voice of the speaker, although a departure from it would in no way affect the delivery of the exact words.

Accordingly, therefore, to the difference in the rate of movement of the cylinder during the reception and reproduction of speech, will be the divergence in tone between the original and the reproduced voice. If the cylinder were moved more quickly in redelivering the words the result would be that they would be in a higher, and, in the opposite case, in a lower key. Probably, as one writer has suggested, the curious effect might be produced of a child's voice being converted into a man's deep base, or _vice versa_.

In view of the results of previous scientific discoveries, we should not be justified in refusing to admit the possibility, at any rate, of the realisation of some of the applications to which its inventor believes the phonograph will, in the course of time, be put.

It must be admitted that these predictions as to its ultimate capabilities are sufficiently wondrous. They are that--the phonograph will be able to record and reproduce at a future time any air sung to it, so that the vocal triumphs of some of our most accomplished singers may be preserved and resung after their death; that by its means may also be conserved and respoken, likewise after death, a speech delivered by a great statesman or orator; that a dying testator by breathing into it his last wishes may have these securely registered, to be expressed after his demise, if need be, in a court of justice; and that the contents of a book or novel may be read to us in the very accents of its author, long after he has pa.s.sed away.

Although we have no testimony that anything like an approach to the above results has been obtained by this instrument, such statements as we possess of its action are not a little surprising.

"Mr Thomas Edison," says the 'Scientific American,' describing this contrivance, "recently came into our office, placed a little machine on our desk, turned a crank, and the machine inquired as to our health, asked how we liked the phonograph, informed us that it was well, and bid us a cordial good night. These remarks were not only perfectly audible to ourselves, but to a dozen or more persons gathered round."

At a meeting of the Physical Society of London, held on the 2nd of March, 1878, when the phonograph was exhibited, the sounds it gave out are said to have been remarkably distinct; and when "G.o.d Save the Queen" was sung as a duet through a double mouth-piece, the two voices could be clearly distinguished on the air being reproduced.

The writer was at the Royal inst.i.tution in Albemarle Street a short time previous to the above date, and although sitting in the top gallery, heard it emit very distinctly the line "Come into the garden, Maud," spoken by Professor Tyndall in compliment to the Laureate, who was present as well as various other vocal reproductions. The secondary sound, however, was less powerful than the original one. The difference between the two is aptly described by a writer in 'Nature,' as causing a feeling like that of looking upon a worn print and an early wood engraving.

"The main utility of the phonograph," says Mr Edison, "being for the purpose of letter-writing, and other forms of dictation, the design is made, with a view to its utility for that purpose.

"The general principles of construction are a flat plate or disc, with spiral groove on the face, operated by clockwork underneath the plate; the grooves are cut very closely together, so as to give a great total length to each inch of surface--a close calculation gives as the capacity of each sheet of foil, upon which the record is had, in the neighbourhood of 40,000 words. The sheets being but 10 inches square, the cost is so trifling that but 100 words might be put upon a single sheet economically.

"The practical application of this form of phonograph for communications is very simple. A sheet of foil is placed in the phonograph, the clockwork set in motion, and the matter dictated in the mouth-piece, without other effort than when dictating to a stenographer. It is then removed, placed in a suitable form of envelope, and sent through the ordinary channels to the correspondent for whom designed. He, placing it upon his phonograph, starts his clockwork, and _listens_ to what his correspondent has to say.

Inasmuch as it gives the tone of voice of his correspondent it is _identified_. As it may be filed away as other letters and at any subsequent time reproduced, it is a perfect _record_. As two sheets of foil have been indented with the same facility as a single sheet, 'the writer' may thus keep a _duplicate_ of his communication.

"The phonograph letters maybe dictated at home or in the office of a friend, the _presence_ of a stenographer _not being required_. The dictation may be as rapid as the thoughts can be formed, or the lips utter them. The recipient may listen to his letters being read at the rate of 150 to 200 words per minute, and at the same time busy himself about other matters. Interjections, explanations, emphasis, exclamations, &c., may be thrown into such letters _ad libitum_.

"The advantages of such an innovation upon the present slow, tedious, and costly methods are too numerous, and too readily suggest themselves, to warrant their enumeration; while there are no disadvantages which will not disappear coincident with the general introduction of the new method."[98]

[Footnote 98: 'North American Review,' May, 1878.]

=PHOS'GENE GAS.= See CHLOROCARBONIC ACID.

=PHOS'PHATE.= _Syn._ PHOSPHAS, L. A salt of phosphoric acid. See PHOSPHORIC ACID and the respective metals.

=PHOS'PHIDE.= See PHOSPHURET.

=PHOS'PHITE.= _Syn._ PHOSPHIS, L. A salt of phosphorous acid. See PHOSPHOROUS ACID.

=PHOS'PHORUS.= P.

_Prep._ This is now only conducted on the large scale:--Bone-ash (in powder), 12 parts, and water 24 parts, are stirred together in a large tub until the mixture is reduced to a perfectly smooth 'pap,' oil of vitriol, 8 parts, is then added in a slender stream, active stirring being employed during the whole time, and afterwards until the combination appears complete; the next day the ma.s.s is thinned with cold water, and, if convenient, heated in a leaden pan or boiler until it has entirely lost its granular character; it is now transferred to one or a series of tall casks (according to the extent of the batch), and further diluted with a large quant.i.ty of water; after repose, the clear liquid is decanted, the sediment washed with water, and the 'washings' and 'decanted liquor'

evaporated in a leaden or copper boiler until the white calcareous deposit (gypsum) becomes considerable; the whole is then allowed to cool, the clear portion decanted, and the sediment thoroughly drained on a filter; the liquid thus obtained is evaporated in an iron pot to the consistence of a thick syrup (say 4 parts), when dry charcoal (in powder), 1 part, is added, and the desiccation continued until the bottom of the pot becomes nearly red hot, after which it is covered over and allowed to cool; the dry mixture, when cold, is put into one or more earthen retorts well covered with 'luting' and properly dried, and heat is applied (sideways rather than at the bottom) by means of a good air-furnace; after a short time the beak of the retort is connected with a copper tube, the other end of which is made to dip about one fourth of an inch beneath the surface of some lukewarm water placed in a trough or wide-mouthed bottle.

The distilled product is purified by squeezing it through chamois leather under warm water, and is then moulded for sale by melting it under water heated to about 145 Fahr., and sucking it up to any desired height in slightly tapering, but perfectly straight, gla.s.s tubes, previously warmed and wetted. The bottom of the tube being now closed with the finger, it is withdrawn, and transferred to a pan of cold water to congeal the phosphorus, which will then commonly fall out, or may be easily expelled by pressure with a piece of wire.

_Prop. &c._ Phosphorus in its normal condition is a pale yellow, semi-transparent, and highly combustible solid; soft and flexible at common temperatures; it becomes waxy at about 75 Fahr.; melts at about 111, and boils at 550 Fahr.; it takes fire in the air at 165, and oxidates at all temperatures above 32. Exposed to the air below 60, its surface is slowly converted into phosphorus acid. It is apparently insoluble in water, but it conveys its peculiar flavour and odour to that fluid when agitated with it; it is slightly soluble in ether, naphtha, and the fixed and volatile oils, and more freely so in bisulphide of carbon.

It unites with oxygen, forming oxides, and with oxygen and hydrogen, forming acids, and with the metals, forming phosphides.

Phosphorus is remarkable for a.s.suming several allotropic forms. In one of these forms (amorphous phosphorus) its properties are so altered that they might be those of a distinct element.